Geometry Storage Format
This article outlines why the storage formats used for geometry data by database spatial APIs are irrelevant: what is important is logical access.
Simon Greener
How to calculate cumulative length of a linestring, or the truck tonnage that accumulates across a set of roads
This articles describes how to compute the cumulative length of a single linestring, or the total tonnage that crosses a set road segments.
Split Oracle Sdo_Geometry Linestring at a Known Point using PL/SQL (1)
This article describes how to split a linestring or a multilinestring using PL/SQL at a known point.
GeoRaptor: Metadata Management
This post documents GeoRaptor’s Metadata Tool that can be used to created, update, delete and analyze the xxx_GEOM_METADATA associated with data held in tables and SDO_GEOMETRY columns.
Geometry object size when exchanging of WKT/WKB encoded geometries.
Introduction The ordinates stored in an geometry objects, across all spatial data types do not have any rounding applied to their values. This is one aspect of data management that is seldom considered by most practitioners. Other articles in this website deal with how to round their values. This article is about a related topic”Read More
Geometry Validity and Method Access
This article demonstrates how an invalid polygon (and linestring) are handled by the different database spatial APIs with correction in TSQL.
My Services
1. Solutions Architecture. I discovered over the years that I am a pretty good systems and solutions architect. How does this apply to you? Well, let’s say you have a business problem you want to be solved. You have a bunch of technology options that provide a framework (or constraint) for delivery, and want toRead More
CheckRadii: Identifying Tight Radius Curves sections within LineString geometry data
Sometimes it is a data quality requirement for linear data (roads, pipelines, transmission lines) that curves within the lines must have a radius greater than a particular amount. Recently a customer asked me to write some TSQL functions to help them run data quality checks over linear data loaded into a SQL Server 2008 geometryRead More
The Sad State of GIS SQL Standards
The background to this blog comes from two separate sources: the first is my testing of SQL Server 2008 “Katmai”, and secondly, a blog article that Charlie Savage wrote a while back on The Sad State of GIS Web Standards. Web Mapping Standards As an ex-GIS Manager who monitored GIS standards for possible deployment withinRead More
Oracle Spatial Mapping and Map Rendering Performance Tips
Comment: This article was written about 10 years ago. Most of what is written is still relevant though the comments about disk usage and access do not apply if SSD is being used. Introduction There are lots of things one can do to improve performance in mapping environments because of a lot of the visualisationRead More